Flush pin gauge



July 10, 1951 y F. w. Kx-:ssLER 25560,???

FLUSH PIN GAUGE Filed Aug. 5, 1949 A' JNVENToR. 27 @ede/zo? M Kessler AITO RN EYS Patented July 10, 1,951

*UNITED `lv vSTATES PATENT OFFICE,

' 2,560,177 FLUsHPlN GAUGE Frederick W.' Kessler, Springfield, Mass. vApplication August 5, 1949, Serial N o. 108,794

v 2 claims. (01.33-169) This invention relates to depth-measuring gauges, and more'particularly to an adjustable, ilush pin gauge for measuring the depth of cavities holes and. counterbores provided in work pieces by machining operations, and the total length or heightof hollow` work pieces, such as bushings, sleeves and similar structures.

Itis among the objectsjof the invention to pro- Vide'an improved flush pin gaugev of vsimpliiied construction whichwill accurately measure the depth of holes, counterbores and cavities in work pieces, and the length of bores and apertures in hollow work pieces, and denitely indicate whether the dimensions measured are Within the prescribed workingtolerances, which is adjustable within extremely wide limits to measure cavities or depressions of diiferentdepths and the total length or height of hollow work piecesof different dimensions, which is easy to adjust and use, and in which the tolerance indication is clearly visible, and which is economical in construction and canlbe readily providedV inrsets of gauges of different sizes for different weight classes of work pieces. y

Other objects and advantagesiwill become apparent from a consideration of the following, description and the appended claims in conjunction with the accompanying drawing, wherein:

Figure 1 is a side elevation of a ilush pin gauge assembly illustrative of the invention;

Figure 2 is a top plan viewof the ilush' vpin gauge assembly illustrated inFigure l;

, Figure 3 isa transverse cross-section onthe linek 3-3 of Figure y1;,and

Figure 4 is a longitudinal cross-sectionalview of a somewhat modiedform of plug andv pin sub-` comprises, in general, an elongated gauge bar I having a sleeve-receiving hole therethrough substantia'llyA at its mid-length location, a sleeve II received in the holeprovided in the gauge bar, a hollow, internally screw-threaded plug I2 slidable in ther sleeve, and a screw-threaded pin I3 threaded into the hollow plug, the plug and pin cornponents Vof the plug and pin sub-assembly in the somewhat modied arrangement, shown in Figure, 4, being yindicated by, thef'reference numerals I2 and I3.

The bar Iis an elongated body of suitable material, such as tool steel, and ispreferably of rectangular cross-section with four-.flat sides, the opposite sides being substantially parallel to each other, and :the `topand bottom^sides of the bar are absolutely straight within thelimitations of the.

most exact Vmanufacturing methods. This. bar has a hole inthe 'form of anelongated slot `I Ilextend'ing therethrough between its top andlbottom s id'es, vand from alo-cation adjacent one end of the 'bar 'to Va location byond'the mid-length locaand without screwthreads.

tion of the bar from said one end. VThe width of the slot is such as to leave, at its opposite sides, opposedside walls I5 having a thickness suiiicient to insure` absolute rigidity of thebar whilein use. The ends of the slotV I4 are arcuately rounded, as particularly illustrated in FigureY 2, and the hollow, cylindrical sleeve II is received in, and extends vthrough the` slot I4 in the bar. At its end adjacent the upper side of the bar, the sleeve II is provided with an outwardly-extending, external ange, I6 which rests upon the upper-edges of the side walls I5 at the opposite sides of the slot. I4; and kat its opposite or lower end,` this sleeve is providedwith an externally screw-threaded portion I'I. A nut I8 is threaded upon the screw-threaded portion I'I .of the sleeveand bears against the bottom edges of the side walls I-5fto rmly clamp the sleeve in adjusted positionlengthwise of the slot I4.

The hollow, internally. screw-threaded plug I2` is sldably received in the sleeve II, and has an external diameter substantially equal to .the internal diameter ofthe sleeve. v

The screw-threaded plug l2 has a cylindrical head I9 with an outside diameter substantially equal to the inside diameter of the sleeve II,

I9, a reduced, cylindrical pertionf22 of the pin extends into a reduced portion 23 of the bore of the plug, `the extension 2.2 of the pin and the reduced extension 23 of the plug bore being smooth The distance from the'fneck 2'0 of the pin to the outer end' of the reduced extension 22 lof the latter is slightly less than the length of the bore in the plug I2, so that the pin canbe threaded fully into the bore ofA the plug and can be threaded outwardly of the plug bore to adjustably vary the .length ofthe pin and plugy assembly.

Theplug and pin assembly has, at its end 'adjacent the flanged end of the sleeve II, two

surfaces '24 ,and 25, each of which has an area substantially equal. to one-half the area of the bore of the sleeve II, and both of which are disposedsubstantially. perpendicular to the longitudinal center-lineof the pin and plug assembly. These two surfaces 24 and` 25 are spaced apart longitudinally of the longitudinal center-line of the. pin and plug assembly a distance substantially equal'to the prescribed working tolerance of vthework which `the gauge is used to measure.

In .the formof the device illustratedrin Figure 3, the pin islocked in adjusted position relative to the plug by suitable means, such as the set screwr26 [which is threaded through a screwthreaded aperture provided in the wall of the 3 plug and bears at its inner end against the reduced extension 22 of the pin.

The pin and plug assembly has, at its end opposite the gauge surfaces 24v and 25, a plane, work or table-contacting surface 21 which is also preferably disposed perpendicular to the longitudinal center-line of the assembly, but this work'- contacting surface may be rounded or otherwise shaped for special measuring operations, if found necessary or desirable. j

In the somewhat modified ,plug and pin as-Y sembly illustrated in Figure 4,the gauge surfaces 24 and 25 are provided on one end of the cylindrical plug I2', which plug is provided with an internally screw-threaded ,bore 28 opening to the end of the plug opposite the gauge surfaces. The'pin I3', in this case, is an externally screw:Y threaded screw or bolt having, at one end, a flat head 29. The pin I3 is threaded into the bore 2,8 ofthe plug l2', and a lock nut 30 threaded onto the pin bears ,against the end ofthe plug at which the bore 28 opens, to lock the pin in adjusted position relative tothe plug. This lock nut 30 preferably has a conical face 3|V facing.

the plug, and the plug is chamferedy around the end of the bore 28 to provide a seat for this conical face of the lock nut.

In use, the pin and plug assembly is adjusted by means of a suitable master gauge or vmicrometer to the length desired. This length is `the desired depth of the cavity in the work piece, or the desired height of a hollow work piece plus the width of the gauge block I0, which width is an exactly even dimension, so that it can be easily added to the desired work piece dimension to determine the total length of the pin and plug assembly. For example, the width of the gauge block may be exactly one inch, exactly one centimeter, or any multiple or even fractionv is adjusted to the proper length and, with the bottom side ofthe gauge bar resting on the top,

of the work piece, the bottom end of the pin and plug assembly is brought into contact with the bottom of the cavity in the work piece. If the surface of the fianged'end of the sleeve Il is nowrbetween the surfaces '24 and 25 of the pin and plug assembly, the depth of the cavity is within the prescribed working tolerances.

In order to measure the total height of such aV hollow work piece, the sleeve may be moved longitudinally of the slot to bring the pin and plug assembly in registry with an aperture 33 in the work piece and, with the pin and plug assembli7 adjusted to the proper length to measure the proper height of the work piece and with the.

work piece resting upon a flat-topped support or table 34, the lower portion of the pin and plug assembly is lowered through the aperture 33 in the work piece to the surface of the table and it is then determined whether the end surface at the anged end of the sleeve Il is betweenlthe gauge surfaces 24 and 25.4

The pin and plug assemblies, as illustrated in Figures 3 and 4, operate in the same manner in the gauge assembly, the pin and plug sub-assembly illustrated in Figure 3 being somewhat easier to adjust in length, while the modified sub-assem- 2,5eo,177 y 4 f bly illustrated in Figure 4 is somewhat more economical to manufacture.

The invention may be embodied in other specie forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the

scope of the inventionv being indicated by the appended claims rather than by the foregoing description, 'and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. A flush pin gauge comprising a gauge bar provided with a longitudinal-ly extendingY slot intermediate its ends,a sleeve extending through said slot and having one end secured to said'bar, a cylindrical-plug having a bore open at one end and closed at the other end Y slidably vreceived within said sleeve, the bore of said plug having internal threads inwardly from its open endand terminating at a point vspaced from its closed end, the threads extendingradially with respect to the axis of said bore, a pin having oneend-extending into the open end of said bore with its other end positioned adjacent to and'spaced from said open end thereof, said pin -having external threads intermediate its ends to thereby form an intermediate threaded portion in threaded engagement with said internal threads on said bore, and a head arranged adjacent the other end of said pin and having one end secured to the other end of said pin, the other end of said head being provided with two stepped surfaces spaced apart longitudinally of the longitudinal center line of said pin. A

2. A flush pin gauge comprising a gauge .bar provided with a longitudinally extending slot intermediate its ends, a sleeve extending through said slot and having one end secured to said bar, a cylindrical plug having a bore open at one end and closed at the other end slidably received within said sleeve, the bore of said plug having internal threads inwardly from its open end and terminating at a point spaced from its closed end, the threads extending radially with respect to the axis of Asaid bore, a pin having one endextending into the open end of said bore with its other endv positioned adjacent to and spaced from said open end thereof, said pin having external threads in-Y arranged adjacent the other end of said pin and having one end secured tothe other end of saidpin, the other end of said head being provided with two stepped surfacesrlongitudinally of the longitudinal center line of said pin, and a transversely disposed screw threaded into said plug intermediate the ends thereof and engageable with said pin to lock said pin in an adjusted position relative to said plug. Y

FREDERICK W. KEssLER.

REFERENCES CITED l The following references are of record in the le of this patent:

' UNITED STATES PATENTS 

